常温低基质厌氧氨氧化ASBR反应器的快速启动

采用低基质模拟废水〔NH_4~+-N、NO_2~--N分别为(25±0.4)、(33±0.6)mg/L〕,在温度为(23±0.5)℃的条件下,研究了厌氧氨氧化ASBR反应器的快速启动。第Ⅰ阶段HRT为24 h,pH不控制,菌体自溶期出水NH_4~+-N为69 mg/L,活性停滞期出水NH_4~+-N与进水几乎相等;第Ⅱ~Ⅲ阶段,菌体处于活性提高期,HRT分别为12、8 h,pH控制为8.0~8.2,出水NH_4~+-N降低到1.6 mg/L,NO_2~--N均先升高后降低;第Ⅳ阶段HRT为4 h,pH控制为8.0~8.2,出水NH_4~+-N和NO_2~--N均低于1 mg/L,TN去除负荷为352.3 mg/(L·d),△m(NH_4~+-N)∶△m(NO_2~--N)∶△m(NO_3~--N)=1∶(1.33±0.02)∶(0.26±0.02),反应器启动成功。     

基质比对厌氧氨氧化生物膜工艺脱氮效能的影响

首先采用厌氧氨氧化生物膜反应器建立稳定的厌氧氨氧化处理系统,控制温度为(32±2)℃,pH为(7.2±0.2)。通过控制进水基质比(NO_2~--N/NH_4~+-N)分别为1:1、1:1.1、1:1.2、1:1.32和1:1.4来研究基质比对厌氧氨氧化生物膜工艺脱氮效能的影响,在基质比1:1.20时,生物膜反应器的脱氮效果最好,进水NH_4~+-N为150 mg/L,HRT为12 h,其出水的平均NH_4~+-N和NO_2~--N在质量浓度分别为6 mg/L和3.5 mg/L,NH_4~+-N和NO_2~--N的平均去除率分别为96%、98%,此时的脱氮性能最好且稳定,其发生反应的NO_2~--N/NH_4~+-N最接近厌氧氨氧化反应式中的1.32。     

HRT、DO和有机物对厌氧氨氧化脱氮性能的影响研究

对厌氧氨氧化的脱氮效果受HRT、溶解氧和有机物的影响情况进行研究。采用人工配水,控制pH为7.5～8.0,温度为(35±1)℃,进水NH_4~+-N、NO_2~--N质量比为1∶1.32,通过进水脱氧和不脱氧改变溶解氧的浓度,有机物影响试验采用厌氧瓶静态试验。以总氮平均负荷为0.472 kg/(m~3·d)为前提条件时,得到复合式UASB厌氧氨氧化反应器的最适宜HRT为12 h;改变条件,当溶解氧为0.7～1.0 mg/L,虽然反应受到影响,但还可以稳定运行;将DO降到(0.2±0.1) mg/L,经过一段时间的反应,厌氧氨氧化反应的处理效果恢复;再次改变进水COD为50～150 mg/L,NH_4~+-N去除率可维持在75%以上,NO_2~--N去除率可达90%以上,COD去除率最低可达到74%,仍保持在较高水平。对于厌氧氨氧化脱氮效果的影响,HRT、溶解氧较大,有机物较小。     

基质含量对人工快渗滤池厌氧氨氧化脱氮的影响

采用人工快渗滤池处理低基质含量污水,考察了进水NO_2~--N、NH_4~+-N含量对厌氧氨氧化(ANAMMOX)脱氮性能的影响。结果表明,人工快渗滤池在进水ρ(NO_2~--N)/ρ(NH_4~+-N)为1.3时ANAMMOX脱氮效果最佳,NH_4~+-N、NO_2~--N、TN平均去除率分别高于98%、98%、91%。对ANAMMOX活性开始产生抑制作用的NH_4~+-N、NO_2~--N质量浓度分别约为65、40 mg/L。提高进水NH_4~+-N、NO_2~--N的质量浓度分别至100、50 mg/L时,ANAMMOX性能受到严重抑制,TN平均去除率分别降至62.2%、45.7%。受NO_2~--N严重抑制时,降低进水NO_2~--N的质量浓度至26 mg/L运行21 d后,TN去除率可恢复至受抑前的84.9%;受NH_4~+-N严重抑制时,降低进水NH_4~+-N的质量浓度至20 mg/L运行16 d后,TN去除率可恢复至受抑前的96.3%。NO_2~--N对ANAMMOX的抑制效应比NH_4~+-N更强,所需的恢复时间更长。     

常温条件下ABR启动运行Anammox性能研究

采用厌氧折流板反应器(ABR)接种好氧活性污泥在常温((25±1)℃)下启动运行厌氧氨氧化工艺。结果表明,启动阶段,控制进水NH_4~+-N和NO_2~--N均为50 mg/L,仅运行57 d,NH_4~+-N、NO_2~--N和TN去除率就分别达到93.82%、99.84%和88.22%,表明成功实现常温启动。负荷提升阶段,73～87 d,进水NH_4~+-N和NO_2~--N的质量浓度以每次50 mg/L的增幅逐步从50 mg/L提升到200 mg/L,每次负荷提升,出水NH_4~+-N和NO_2~--N含量小幅波动再趋向于稳定,表明ABR有一定的耐负荷冲击能力。运行93 d,最大TN负荷率和TN去除速率分别为0.40 kg/(m~3·d)和0.33kg/(m~3·d),表现较好的脱氮性能。可为厌氧氨氧化工艺在实际工程中的应用提供理论依据。     

短程硝化与厌氧氨氧化装置启动及连接过程研究

探究了2种工艺稳定高效启动方法,以及两装置的连接方式及进水改变对总出水的影响。分别启动厌氧氨氧化于短程硝化装置,调整负荷水质以使短程硝化出水满足厌氧氨氧化装置进水要求。短程硝化装置以进水pH=8.4、NH_4~+-N的质量浓度170 mg/L、亚硝氮生成率为14.4 mg/(L·h)启动,亚硝氮积累率稳定在85%以上。厌氧氨氧化装置以进水NH_4~+-N、NO_2~--N的质量浓度分别为150、198 mg/L,HRT为24 h,TN去除率84%启动并稳定。装置连接后,厌氧氨氧化装置进水由人工配水改为短程硝化出水调配水,相较原进水COD残余约80 mg/L,NO_3~--N的质量浓度15 mg/L,TN去除率有些微的提升,但COD对成熟的厌氧氨氧化装置影响还有待检测。成熟稳定的厌氧氨氧化装置可以很好地适应短程硝化出水调配水,并对进水水质变化具有较好的耐受性。     

水力停留时间对厌氧氨氧化脱氮性能的影响

为研究HRT对厌氧氨氧化脱氮性能的影响,确定在HRT条件下实现厌氧氨氧化的运行参数。笔者采用模拟亚硝化进水,消化池污泥作为接种污泥,在UASB反应器中控制温度为30~35℃,pH为7~8,通入氩气进行脱氧,分别在不同HRT(3 h、6 h、12 h、24 h、48 h)条件下运行一周时间,考察TN、NH_4~+-N与NO_2~--N的去除率与TN容积负荷,从而确定最佳HRT。试验结果显示,当HRT为12h时,能较好地发挥厌氧氨氧化菌的活性,得到较好的污水处理效果。试验采用UASB反应器成功启动并运行了厌氧氨氧化工艺,具有较高的脱氮性能,为厌氧氨氧化的稳定运行提供数据支持。     

外源磷对厌氧氨氧化启动及富集的影响

为研究外源磷对厌氧氨氧化启动及富集过程的影响,采用接种常规活性污泥进行厌氧氨氧化启动实验。结果表明,无外源磷的条件下接种普通活性污泥可以启动厌氧氨氧化并完成厌氧氨氧化菌富集,启动所需的时间相比于有外源磷的条件的时间更长,富集后在进水NH_4~+-N、NO_2~--N的质量浓度分别为150、180 mg/L条件下,NH_4~+-N和NO_2~--N去除率稳定在95.07%和95.97%,△ρ(NO_2~--N)/△ρ(NH_4~+-N)稳定在1.2;无外源磷可缩短启动过程中的菌体自溶的时间;无外源磷条件下厌氧氨氧化启动活性提升阶段基质去除率增长较慢,培养40 d,NH_4~+-N去除率由6.29%增长至34.50%。     

膜生物反应器中厌氧氨氧化的启动研究

为探究膜生物反应器(MBR)进行厌氧氨氧化的可行性及性能,通过逐渐提高进水NH_4~+-N、NO_2~--N的含量和降低HRT,成功启动了自流出水式MBR厌氧氨氧化过程,分析了反应器脱氮效果和厌氧氨氧化污泥特性,并采用扫描电镜和X射线光电子能谱中空纤维膜表面进行分析。结果表明,经过60 d的启动,NH_4~+-N、NO_2~--N和TN的去除率分别达到96.22%、99.91%和81.66%,TN去除负荷最大可达到330 g/(m~3·d)。在启动过程中,污泥颜色逐渐变为红褐色;中空纤维膜表面厌氧氨氧化菌呈不规则的椭球状,结构紧凑;MBR运行稳定阶段末期中空纤维膜表面C、N和Ca特征峰增多,是膜污染化学组分的主要构成元素。     

升流式厌氧氨氧化流化床反应器脱氮效能研究

采用升流式厌氧流化床反应器,研究高浓度厌氧氨氧化工艺的脱氮效能。接种普通好氧活性污泥,以低浓度配水(NH_4~+-N 60 mg/L,NO_2~--N 50 mg/L)驯化厌氧氨氧化菌,经150 d富集,填料表面形成红色生物膜,NH_4~+-N和NO_2~--N同步去除率高于80%,反应器成功启动;采用低基质进水(NH_4~+-N 60～300 mg/L,NO_2~--N 100～355 mg/L),随着进水容积负荷的增加,总氮去除负荷从0.39 kg/(m~3·d)提升至1.29 kg/(m~3·d);采用高基质进水(NH_4~+-N 390 mg/L,NO_2~--N 400 mg/L)时,总氮去除负荷降至1.08 kg/(m~3·d),150%回流能有效缓解基质对厌氧氨氧化菌的活性抑制,反应器总氮去除负荷逐渐恢复并升高至1.76 kg/(m~3·d),脱氮效能提高63%。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。